In a remarkably positive use of artificial intelligence, New Zealand filmmaker and life-long Beatles fan Peter Jackson has made a valuable contribution to the last Beatles song becoming a reality.

A newly released 12-minute mini documentary, Now And Then – The Last Beatles Song (YouTube, Disney+) reveals Jackson used his audio separation technology to extract Lennon’s voice from the piano from a 1970s demo tape.

Given to the band by Yoko Ono in the 1990s, the surviving Beatles, Paul McCartney, Ringo Starr and the late George Harrison started trying to extract Lennon’s voice.

They were already working on Free as a Bird and Real Love for their Anthology project, but Lennon’s voice on Now and Then was muddy.

“Every time we wanted a little more of John’s voice, this piano came through and clouded the picture,” McCartney says in the short film.

“I think we kinda ran out of steam a bit, and time.

“Now and Then languished in a cupboard … then in 2001 we lost George which took the wind out of our sails and it took almost a quarter of a century for us to wait until the right moment to tackle Now and Then again.

Having already worked on the acclaimed 2021 Beatles: Get Back documentary series for which he used his MAL (machine audio learning) software, McCartney asked Jackson to try and separate Lennon’s vocal and piano after they’d come to realise “he’d been able to separate off certain instruments and voices”.

“During the course of Get Back we were paying a lot of attention to the technical restoration and that ultimately us to develop a technology which allows us to take any soundtrack and split all the different components into separate tracks based on machine learning,” Jackson explains.

“They said, this is the sound of John’s voice. A few seconds later … there it was. John’s voice, crystal clear … we took John off and gave him his own track. It’s like John’s there, you know – it’s far out.

“So in the mix, we could lift John’s voice without lifting the piano, which had always been one of the problems. Now we could mix it and make a proper record of it. I pulled it out, had a listen to it, and thought, ‘Oh, I could actually do the bass a bit better. So why don’t I start there’?”

Besides Lennon’s vocal, this song has electric and acoustic guitar recorded in 1995 by George, Ringo’s new drum part, and bass, guitar and piano from Paul recorded last year and which matches John’s original playing.

Paul added a slide guitar solo inspired by George. He and Ringo also contributed backing vocals to the chorus.

“Let’s say I had a chance to ask John, ‘Hey John, would you like us to finish this last song of yours?’ I’m telling you, I know what the answer would’ve been.

“Yeah! He would’ve loved that.”

‘Almost too overwhelming to deal with’

Jackson was also tasked with making a music video for the song and says it was almost “too overwhelming to deal with”.

“My life-long love of The Beatles collided into a wall of sheer terror at the thought of letting everyone down,” he says on the official Beatles website.

“This created intense insecurity in me because I’d never made a music video before, and was not able to imagine how I could even begin to create one for a band that broke up over 50 years ago, had never actually performed the song, and had half of its members no longer with us.

“It was going to be far easier to do a runner.

“A Beatles music video must have great Beatles footage at its core. There’s no way actors or CGI Beatles should be used. Every shot of The Beatles needed to be genuine.”

After searching through 14 hours of footage from those 1995 recording sessions, some unseen home movie footage from the family, and The Beatles performing in leather suits, Jackson changed his mind.

The music video will be released this week.

The Beatles played about 250 gigs at The Cavern in London in the early 1960s. Photo: Getty

Stacked with archival vision from the 1960s and the mid-’90s session when they completed the first two songs unearthed from Lennon’s demo, we also hear from Lennon’s son, Sean Ono Lennon.

“It was incredibly touching to hear them working together after all the years that Dad had been gone. It’s the last song my dad, Paul, George and Ringo got to make together.

“It’s like a time capsule and all feels very meant to be,” he said.

McCartney and Starr both speak about how emotional it was to have the four musicians reunite one last time.

“There it was, John’s voice, crystal clear. It’s quite emotional. And we all play on it. It’s a genuine Beatles recording. In 2023 to still be working on Beatles music, and about to release a new song the public haven’t heard, I think it’s an exciting thing,” McCartney said.

Adds Starr: “It was the closest we’ll ever come to having him back in the room, so it was very emotional for all of us. It was like John was there, you know.

“It’s far out.”

Now And Then will be released at 1am AEDT on Friday, November 3